148 NOTO THERIUM Cuscuses.1 The dental formula is I -f- C -J- Pm f- M -|; the last premolar is a great blade-shaped tooth like that of Potorous. jtfbtotherium was a creature smaller than Diprotodon, but still of large size; it is helieved to have been a burrowing creature, and to connect the Wombats with Diprotodon. More certainly allied to the existing Wombat was Pfoascolonus, a Wombat as big as a Tapir. Of extinct American Diprotodonts the Epanorthidae, already referred to in connexion with the living Caemolestes, were the most FIG. 75. (After Owen.) prominent forms. The genus EpanortTius occurs in the Santa Cruz formation of Patagonia, which is believed to be Miocene. The incisors are three in the upper jaw ; and the single incisor of each ramus of the lower jaw is a great chisel-shaped, cutting instrument. Alderites is also typically Biprotodont by reason of the large projecting incisors of the lower jaw. It has a large cutting tooth in the lower jaw, which appears to be the last premolar, and is thus comparable to the vgreat cutting tooth of the lower jaw aud of the upper jaw of the extinct Fhalanger, Thylacoleo. ,* Quite recently (Proc. Linn, Soc. NmS. W. 1898, p. 1) the carnivorous character of Tkylaeoileo lias been reasserted "by Mr. Broom.